This invention relates to an adjustable pedal system for an automobile.
Adjustable pedal systems are known in the art. These adjustable pedal systems allow the driver to adjust the position of the brake and accelerator pedals (and clutch pedal in automobiles with manual transmissions) fore and aft for greater comfort and for greater distance from a steering wheel mounted air bag.
These adjustable pedal systems often comprise a jack screw actuator for each adjustable pedal and in some instances the rotary screws, also known as threaded members, of several jack screw actuators are rotated by a common power source, such as an electric motor. See for instance, U.S. Pat. No. 4,870,871 granted to Steve D. Ivan Oct. 3, 1989; U.S. Pat. No. 5,460,061 granted to Harry L. Redding et al Oct. 24, 1995 and U.S. Pat. No. 5,722,302 granted to Christopher J. Rixon et al Mar. 3, 1998.
The Redding ""061 patent and the Rixon ""302 patent both disclose arrangements that have two flexible, torsionally rigid cables that transfer drive from a single power source, an electric motor, to two jack screw actuators, each of which adjusts a different pedal. A drawback of these adjustable pedal systems is that one pedal can be adjusted while the other pedal remains stationary if one of the power transfer cables breaks. This results in pedal misalignment which in turn may result in an awkward and uncomfortable operation for the vehicle driver.
The adjustable pedal system of this invention has a single power source, such as an electric motor that drives a plurality of jack screw actuators with flexible, but torsionally rigid, cables. Each pedal is driven by one of the jack screw actuators that is driven by one of the cables. An aligned forexe2x80x94aft location of the various pedals, such as the accelerator pedal and the brake pedal (i.e. pedal step-over) must be maintained within certain desirable limits. The adjustable pedal system of the invention maintains the fore-aft alignment of the various pedals by controlling the electric motor with a fail-safe device that is mechanically connected to the adjustable pedals; the device being operated when the adjustable pedals are out of alignment by a predetermined amount to de-energize the electric motor. This feature prevents pedal misalignment during the adjustment process even if one of the drive cables breaks so that one of the pedals is not moved by its associated jack screw actuator during the adjustment process.